code: def export_if() -> None:
      # Given a bool scalar input cond.
      # return constant tensor x if cond is True, otherwise return constant tensor y.
  
      then_out = onnx.helper.make_tensor_value_info(
          "then_out", onnx.TensorProto.FLOAT, [5]
      )
      else_out = onnx.helper.make_tensor_value_info(
          "else_out", onnx.TensorProto.FLOAT, [5]
      )
  
      x = np.array([1, 2, 3, 4, 5]).astype(np.float32)
      y = np.array([5, 4, 3, 2, 1]).astype(np.float32)
  
      then_const_node = onnx.helper.make_node(
          "Constant",
          inputs=[],
          outputs=["then_out"],
          value=onnx.numpy_helper.from_array(x),
      )
  
      else_const_node = onnx.helper.make_node(
          "Constant",
          inputs=[],
          outputs=["else_out"],
          value=onnx.numpy_helper.from_array(y),
      )
  
      then_body = onnx.helper.make_graph(
          [then_const_node], "then_body", [], [then_out]
      )
  
      else_body = onnx.helper.make_graph(
          [else_const_node], "else_body", [], [else_out]
      )
  
      if_node = onnx.helper.make_node(
          "If",
          inputs=["cond"],
          outputs=["res"],
          then_branch=then_body,
          else_branch=else_body,
      )
  
      cond = np.array(1).astype(bool)
      res = x if cond else y
      expect(
          if_node,
          inputs=[cond],
          outputs=[res],
          name="test_if",
          opset_imports=[onnx.helper.make_opsetid("", 11)],
      )
  
file_path: onnx/onnx/backend/test/case/node/if.py
imports: import numpy
  import onnx
  from onnx.backend.test.case.base import Base
  from onnx.backend.test.case.node import expect
label_desc: Use image node_id 1 for calling the If obj's underlying member method code with example usage: obj.export_if() without return types